Scientific Forecaster Discussion

Synopsis... a cold front will drop south through the region late tonight. High pressure will build north of the region late Wednesday into Wednesday night then pass offshore Thursday. A cold front will approach from the west late Friday and cross the region early Saturday. High pressure will build in from the northwest Sunday and move offshore early next week.

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Near term /until 6 am Wednesday morning/... as of 615 PM Tuesday...a surface low will track southeast through the Middle-Atlantic States and off the Delaware/New Jersey coast this evening with a cold front moving through eastern NC after midnight tonight. A strong shortwave will move through the Middle-Atlantic States and off southern New England overnight...well north of eastern NC. Limited moisture will be associated with the front thus dry conds expected. Winds will shift north after midnight behind the front and may gust upwards of 25 miles per hour along the Outer Banks through late tonight. Lows tonight will range from the middle to upper 40s.

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Short term /6 am Wednesday morning through 6 PM Wednesday/... as of 215 PM Tuesday....dry and sunny for Wednesday with weak high pressure building in from north behind the front. Below normal temperatures expected Wednesday with a cool air mass in place. Temperatures will range from the lower to middle 60s inland western areas to the 50s across eastern sections.

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Long term /Wednesday night through Tuesday/... as of 345 PM Tuesday...roller coaster temperature ride through the long term with mainly dry conditions except on Friday night into Saturday morning associated with a cold frontal passage.

Wednesday night into Thursday...dry period expected with weak high pressure dominating the weather. Very dry airmass and calm winds/clear skies Wednesday night allow for excellent radiational cooling. Lows drop into the middle/upper 30s inland to near 40 coast but think temperatures should be warm enough to preclude frost mention at this time. Return southerly flow on Thursday as high shifts off the East Coast and pleasant afternoon highs in the 70s (60s beaches) with low humidity values.

Thursday night into Friday...trended dry Thursday night as weak short wave swings through but no moisture available to work with. Maintained the slght chance thunder mainly away from the coast on Friday as moisture return increases and could be weak forcing along sea breeze front. Main story Friday though will be gusty SW winds 20-25 knots and very warm temperatures as most locales climb into the low 80s inland (upr 60s/low 70s beaches).

Friday night into Sat...forecast thinking remains generally the same with strong cold front pushing through east NC this period. Warm and breezy Friday night with lows generally in the low 60s. Minor timing differences with frontal passage...with 31/12z GFS slightly faster than the deterministic CMC/ECMWF. Will side with the slightly slower solution and have highest probability of precipitation very late Friday night into first half of Sat. Maintained the 50 probability of precipitation with scattered shower/isolated thunder wording due to convective nature of precipitation. Instability/lapse rates are rather weak so no severe ts expected though strong southwesterly jet overnight Friday night will produce isolated thunder embedded in heavier showers. Quickly drying after around noon Sat with front racing offshore and skies becoming sunny west to east. Highs should reach the upper 60s/low 70s most areas.

Sat night through early next week...broad high pressure will move across area at surface with mainly zonal flow aloft. Lows upper 30s/low 40s Sat night with highs near 60 north obx to upper 60s SW zones. Warming trend early next week as steadily building heights and 850mb temperatures pushes temperatures back above climatology. It will be mainly dry through the period...though GFS appears to be suffering from some convective feedback with fast moving southern stream shortwave propagating through mean flow on Tuesday. Will keep forecast dry at this time.

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Aviation /22z Tuesday through Sunday/... short term /tonight and Wednesday/... as of 615 PM Tuesday...VFR conditions will prevail through the period as high pressure shifts offshore. Southwest winds will be gusty this evening ahead of a cold front approaching from the northwest. The front should shift through eastern NC after 06z Wednesday without impacts on aviation except for a wind shift to north late tonight. High pressure builds in for Wednesday with northerly winds gusting to 15 knots after 12z.

Long term /Wednesday night through Sunday/... as of 345 PM Tuesday...VFR expected to prevail through Friday. Gusty SW winds 15-25 knots on Friday/Friday night ahead of strong cold front. Period of sub- VFR conditions likely late Friday night into Sat morning with scattered showers/isolated thunder ahead of the front. VFR returning by Sat afternoon with clearing skies. The VFR will likely last through the beginning of the week.

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Marine... short term /tonight and Wednesday/... as of 615 PM Tuesday...based on observation will raise small craft advisories through 09z for the Albemarle Sound and the adjacent Alligator river. No other changes planned.

High pressure will shift off the southeast U.S. Coast this evening with southwest winds throughout. Low pressure will move east through the Middle-Atlantic States allowing the SW pressure gradient to increase building winds and seas to Small Craft Advisory levels. SW winds will be 15-25 knots over the coastal waters and sounds and overnight. Small Craft Advisory continues for the coastal waters including the Pamlico Sound. Seas will build to 6 feet for the southern and central outer waters in SW flow...then seas continue above 6 feet tonight with Post-frontal northerly wind shift for the central and northern waters through most of Wednesday.

Long term /Wednesday night through Saturday/... as of 345 PM Tuesday...high pressure building over the waters Wednesday night will bring tranquil conditions. Winds will become srly and increase to 15-20 knots Thursday as high moves offshore. Small Craft Advisory conditions likely again Thursday night into Sat. SW winds 20-30 knots in tightened pressure gradient ahead of cold front...peaking Friday night/early Sat morning. The SW winds switch to the northwest and remain gusty first half of Sat before slowly diminishing. Some minor timing differences in pushing front through...with GFS slightly faster than the CMC/European model (ecmwf) global models...though all models indicate the front being offshore by 18z Saturday. Seas will peak at 8-11 feet late Friday night/early Sat morning...then slowly subside thereafter.